Method of grinding profiles



April 8, 1969 I o. BETZLER 3,436,874

I METHOD OF GRINDING PROFILES Filed Sept. 2. 1966 In venzor O/fe B 6/2e1- United States Patent 3,436,874 METHOD OF GRINDING PROFILES OttoBetzler, Tauberbischofsheim, Germany, assignor to Michael Weinig KG,Tauberbischofsheim, Germany Filed Sept. 2, 1966, Ser. No. 576,900

Claims priority, application Germany, Sept. 6, 1965,

W 39,857 Int. Cl. B24b 13/02, 7/02 US. Cl. 51-325 9 Claims ABSTRACT OFTHE DISCLOSURE The present invention relates to a method of grindingprofiles, especially profile strips of wood, synthetic material, and thelike, according to which a raw grinding tool is provided with acounter-profile which corresponds to the profile to be ground whereuponby means of the thus made grinding tool the profile to be ground isproduced.

Various attempts have been made mechanically to produce profiles bygrinding. The production of the precise counter-profile, however, causesconsiderable difficulties in this connection. This holds true inparticular when the tool which may for instance be blunted or truncated,has to be resharpened or reground, in which instance changes of thecounter-profile within certain tolerances are unavoidable. It is alsoknown to cover correspondingly profiled tools with a, for instance,perforated grinding paper which when becoming dull will be exchanged.However, in view of the specific property of grinding paper, it isimpossible to produce properly sharp edges, large profile recesses,small roundings, and similar specific profiles.

It is, therefore, an object of the present invention to provide a methodof the above-mentioned general type by means of which it will bepossible to grind a profile with high precision and in a simple manner.

It is a further object of this invention to provide a grinding methodwhich will permit the proper grinding of specific profiles, as forinstance sharp edges, large recesses, and small roundings.

It is a further object of this invention to provide a grinding method asset forth above which can be practiced at low costs.

These and other objects and advantages of the invention will appear moreclearly from the following specification in connection with theaccompanying drawing, in which:

FIG. 1 illustrates in perspective view a pattern for use in connectionwith the method according to the present invention.

FIGS. 2 to 6 respectively illustrate individual steps or phases of themethod according to the invention.

A method for grinding profiles, especially profiled strips of wood,synthetic material, and the like, according to which a raw grinding toolis provided with a counter-profile corresponding to the profile to bemade whereupon the profile to be made is produced by the thus builtupraw grinding tool, is characterized in that directly upon a profiledpattern, for instance a model or a remaining piece of the profile to beground, there is applied a grinding or abrasive layer. By means of thethus prepared raw pattern, the raw grinding tool consisting of a lesshard synthetic material, as for instance a material known under thetrademark Styropor, is by grinding provided with the counter-profile. Tothe thus produced profiled grinding tool there is applied an abrasivelayer, and by means of the thus produced abrasive layer covered tool thefinal profile to be made is ground. In this way, it will be assured thatthe grinding tool will in each instance obtain a counter-profile whichprecisely corresponds to the profile finally to be ground. Inasmuch asthe abrasive layer is applied directly to the pattern as well asdirectly to the counter-profile of the grinding tool, also extremeprofiles, such as sharp edges, large profiled recesses, or smallroundings, can be ground in a proper and true manner.

The application of the method according to the invention is economicalnot only with regard to the employed materials for the grinding tool butalso with regard to the time required for the machining.

According to a further feature of the present invention, the grindinggrains or abrasive layer is connected to the pattern and the tool forinstance by an adhesive. In this way a safe and firm connection of thegrinding grains will be assured while selectively various sizes of thegrinding grains may be employed in conformity with the particularpurpose involved.

According to a further development of the present invention, the patternand the grinding tool may be coated with a preferably water solubleadhesive and may subsequently be sprayed with grinding grains of adesired size. In this way, the thickness of the adhesive layer can in asimple manner he so selected that the grinding grains protrude from theadhesive and are firmly held in and bonded to the adhesive. By employinga water soluble adhesive, it is possible after the grinding grainsbecome dull to remove the same from the pattern and grinding tool bymerely washing the pattern and the grinding tool. By means of thewashing process, also the adhesive is removed so that the pattern andthe grinding tool can again be coated by an adhesive and be sprayed withgrinding grains to thereby ready the pattern and tool for further use.

Advantageously, the elasticity of the material of the grinding tool isselected in conformity with the material of the profile to be ground sothat in each instance a favorable grinding will be assured.

When a grinding operation is to be carried out during which considerablematerial has to be ground off, it is advantageous to grind the finalprofile in immediately succeeding steps so that the profile can befinish ground in one Working operation and with one setting. In thisinstance, the grinding tools advantageously have grinding grains whichbecome progressively finer in the feeding direction of the workpiece tobe ground so that the workpiece after a coarse grinding and a smoothgrinding will be provided with a fine finish grinding. The granular sizeof the grinding grains of the successive tools may in this instance befor instance 80, 100, 150, 200.

It is also possible at the circumference of the profile to be ground,for instance of the strip to be ground, to provide a plurality of toolsso that the profile strip will be ground in a single working operationfrom all sides.

With the method described above, it is possible to employ rotatinggrinding discs as well as reciprocating grinding tools. The grindingtools may also without difiiculties be post-ground according to apattern in the manner described above. In other words, if the profile byuse of the tool has worn off or has been damaged, it can again bemachined or sharpened (post-ground) in conformity with the invention setforth above.

Referring now to the drawing in detail, FIG. 1 shows a pattern 1 havinga profile 2 corresponding to the profile to be produced. The pattern 1may be a remaining piece of a finished profile. The pattern 1 is withinthe range of the profile 2 provided with a thin adhesive layer 3 (FIG.2) which may for instance be sprayed upon the pattern 1. The thus coatedprofile 2 is then in conformity with FIG. 3 sprayed with grinding grains4 which at least partially sink into the adhesive layer 3 and afterhardening of said layer 3 will be firmly bonded and held to the pattern1.

A raw grinding tool, for instance in the form of a grinding disc 5, isthen rotated about its axis and moved in radial direction as indicatedby the arrow 7 toward the pattern 1 prepared in conformity with thesteps described in connection with FIGS. 1, 2 and 3. This raw grindingtool may consist for instance of a foamed polystyrol, as it is marketedunder the trademark Styropor. While the grinding disc 5 is moved in thedirection of the arrow 7 toward the prepared pattern 1 as shown in FIG.4, at the same time a relative movement between the pattern 1 and thegrinding tool 5 in the longitudinal direction of the pattern 1 (seearrow 6 of FIG. 1) is eifected. As a result thereof, the grinding tool 5will be provided with a counter-profile 2a which precisely correspondsto the profile 2 of pattern 1.

Grinding tool 5a is now within the range of the counter-profile 2aprovided with a granular layer 4a of grinding grains which in the mannerdescribed above in connection with pattern 1 and FIG. 3 is held on thegrinding tool 5 by an adhesive. Consequently, after the adhesive layer3a with the grinding grains has solidified, the thus created grindingtool 5a (FIG. 6) will then be used for grinding a workpiece 1a in orderto provide the same with a profile corresponding to the counter-profile2a. It will be appre ciated that the thus created profile in workpiece1a will precisely correspond to the profile 2 of pattern 1.

In FIGS. 2 to 6 the thickness of the adhesive layers 3, 3aand of thelayers 4, 4a of the grinding grains has been illustrated on a somewhatlarger scale than the actual size in order more clearly to show theinvention.

It is, of course, to be understood that the present invention is, by nomeans, limited to the particular method set forth herein but alsocomprises any modifications within the scope of the appended claims.

What I claim is:

1. A method of grinding a profile into workpieces, especially of woodand of synthetic material, which includes the steps of: preparing apattern profile precisely in conformity with the eventual profile to beground into a Workpiece, applying a layer of grinding grains directlyonto the profiled surface of said pattern, pressing an unfinished toolof a hardness less than the hardness of the grinding layer thus appliedto said pattern against said applied grinding grain layer whilesimultaneously effecting a relative movemnt between said unfinished tooland said pattern for providing said unfinished tool with a counterprofile forming a negative of the profile of said grinding grain layercovered pattern, directly applying to the thus created counter profiledsurface of said tool a layer of grinding grains, and by means of thethus produced counter profiled tool grinding into the workpiece to beprofiled a profile corresponding to that of said pattern.

2. A method according to claim 1, in which the layer of grinding grainsdirectly applied onto the profiled surface of said pattern is connectedthereto by bonding.

3. A method according to claim 1 according to which the layer ofgrinding grains directly applied to the created counter profiled surfaceof the tool is connected thereto by bonding.

4. A method according to claim 1, which includes the steps of: applyinga water soluble adhesive directly onto the profiled surface of saidpattern, and subsequently spraying grinding grains onto the thus treatedprofiled surface of said pattern.

5. A method according to claim 1, which includes the steps of: directlyapplying to the counter profiled surface of the tool a water solubleadhesive, and subsequently spraying grinding grains onto the thustreated counter profiled surface of said tool.

6. A method according to claim 4, in which for replacing the watersoluble adhesive with the grinding grains therein by a new layer of awater soluble adhesive with grinding grains, the layer of water solubleadhesive with grinding grains to be replaced is washed off whereupon anew layer of adhesive is applied to the pattern and new grinding grainsare sprayed onto the thus applied adhesive.

7. A method according to claim 5, in which for replacing the watersoluble adhesive with the grinding grains therein by a new layer of awater soluble adhesive with grinding grains, the layer of water solubleadhesive with grinding grains to be replaced is washed off whereupon anew layer of adhesive is applied to the tool and new grinding grains aresprayed onto the thus applied adhesive.

8. A method according to claim 1, which includes the step of: selectingthe elasticity of the material for the unfinished tool in conformitywith the material of the profile to be ground.

9. A method according to claim 1, which includes the step of effectingthe grinding of the workpiece to be provided with a profilecorresponding to the pattern in successive operations by means of aplurality of tools when considerable material has to be ground off fromthe workpiece.

References Cited UNITED STATES PATENTS 151,847 6/ 1874 Cochran 51-2931,991,069 2/ 1935 Turner 51-325 2,226,608 12/ 1940 Gilmore et al 51-2932,320,569 6/1943 Conrady 51293 2,351,842 6/1944 Seibold 5l60 LESTER M.SWINGLE, Primary Examiner.

US. Cl. X.R. 5l293

